Apparatus for sharpening saws.



No. 735,100. PATBNTED'AUG. 4, 1903.

, J. HORMBY. APPARATUS FOR SEARPENING SAWS.

APPLIOATION FILED 0012.25, 1902.

N0 MODEL.

wlTNEssEs: A iNvENToR 9@ ATTORNEY UNITED STATES Patented August 4, 1903. PATENT OFFICE.

JOHN HORMBY, OF VVOONSOOKT, RHODE ISLAND.

APPARATUS FOR SHARPENING SAWS.

SEEGIFICATION forming part of Letters Patent No. 735,100, dated August 4, 1903.

Application filed October 25| 1902. Serial No. 128,833. (No model.)

To all whom, t Netty concern.-

Be it known that I, JOHN HORMBY, a citizen of the Unit-ed States, and a resident of the city of Woonsocket, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Apparatus for Sharpening Ivory-Unt Saws, of which the following isa specification.

My invention relates to an apparatus for sharpening ivory-nut saws, and its novelty consists in the construction and adaptation of the parts, as will be more fully hereinafter pointed out.

The ivory-nuts referred to are very hard and any saw employed upon them must constantly be kept sharp and with the extreme edges of the cutting-teeth of uniform'radius; otherwise an edge of one tooth will miss the work and the next edge will dig into the nut or piece of nut and throw it out of the grasp of the operator and probably cut him, if it does not otherwise injure him. Skilled labor has heretofore commonly been employed to sharpen saws of this character. My device is designed to enable cheaper labor to be used for this purpose and at the same time to secure uniformity of depth in the cutting edges of the saw-teeth. Several requirements must be fulfilled in order to secure the desired result. .The sharpening-file must be drawn against the teeth in a direction oblique to the cutting plane of the saw. It must be guided in this oblique plane and kept there or parallel thereto. lt must be permitted to move freely and at the same time the saw must be iirmly held during the operation. The support for the file must also be adjustable, so that as the saw is worn down and the cutting radius becomes less the lile will still be held in its proper position. l believe that all of these requirements are met by my improved sharpening device.

In the drawings, Figure 1 is a top plan view of my sharpening device, the saw, and its connections. Fig. 2 is a side elevation of the same; and Fig. 3 is a front elevation of the file-support, showing the lile in position.

In the drawings, 10 is a circular saw suitably mounted upon a horizontal shaft ll and actuated by a pulley 12. It is adapted to be covered by a hood 13, hinged at 14 to -a lug l5, secured to or made integral with a baseplate 16, which is mounted upon a standard or pedestal. (Not shown.) Secured to the one side of the base-plate 16 are two projecting guides 17 17, adapted to engage with and hold in position a shoe 2O of a bracket 2l. The shoe 20 is internally threaded to receive a threaded post 22, adapted te be moved up and down by the rotation of an adjusting thumbnut 23, while a jam-nut 24 holds the post firmly in position after adjustment. On top of the post 22 is mounted the bracket proper. It consists of ahorizontal member 30 and upwardly-curved member 3l and two outwardlyprojecting posts 32 32, each terminating in vertical flanged plates 33 33, which constitute tile-guards. The posts 32 32 each carry pins, (not shown,) on the outer ends of which are mounted conical rollers 34 34, secured in place by screws 35 35. The curved member 31 is so shaped as to clear the saw and bring the uppermost point of the plane of intersection between each guard 33 and its roller 34 tangent to a line which passes through the deepest point of one of the saw-teeth. This member 31 is placed oblique to the plane of the saw in order that the file 40 when placed in position may rest against the guards 33 33 and upon the rollers 34 34.

The rollers are made of any suitable material; but the plates 33 33 are preferably made of hardened steel, so as not to be materially affected by the rubbing of the le.

The saws employed in the art referred to are very thin and are apt to buckle when sharpened. To prevent this, I provide a bearingplate 50, projecting outwardly from the member 3l of the bracket and against which the saw can be held while being sharpened. On top of the bearing-plate it is provided with the registering spring 51, the free end of which fits into the depression of each tooth and holds it against accidental rotation.

l. A sharpening device for ivory-saws comprising a bracket adapted to be secured upon the saw-frame, two rollers projecting therefrom and having their axes in planes oblique to the cutting plane of the saw and a tile-guard secured to said bracket adjacent to the rollers and in a plane at a right angle to their axes.

2. A sharpening device for ivory-saws consisting of the combination of a bracket secured to the saw-frame, a plurality of posts projecting from the bracket oblique to the cutting plane of the saw and each terminating in a file-guard, and a roller mounted loosely to rotate in front of each file-guard.

3. A sharpening device for ivory-saws comprising a bracket adapted to be secured upon the saw-frame, two rollers projecting therefrom and having their axes adjustable in planes oblique to the cutting plane of the saw, a file-guard secured to said bracket, and always held in a plane at a right angle to the axes of the rollers.

4, A sharpening device for ivory-saws con` sisting of the combination of a bracket secured to the saw-frame, a plurality of posts projecting from the bracket oblique to the cutting plane of the saw and each terminating in a file-guard, a roller mounted loosely to rotate in front of each ile-guard, and a bearing-plate for the saw.

5. A sharpening device for ivory-saws comprising the combination of a bracket, two pins projecting therefrom, two conical rollers loosely mounted to rotate upon said pins and file-guards also mounted on the same bracketl the faces of which are in a plane at an angle to the axes of the conical rollers.

6. A sharpening device for ivory-saws comprising the combination of a bracket, two pins projecting therefrom, two conical rollers loosely mounted to rotate upon said pins and file -guards rigidly mounted on the same bracket the faces of which are in the same plane at an angle to the axes of the conical rollers.

7. A sharpening device for ivory-saws comprising a bracket adapted to be secured upon the saw-frame, two rollers projecting therefrom and having their axes in planes oblique to the cutting plane of the saw, a file-guard secured to said bracket, and means for adjusting the bracket and holding it in place after adjustment.

8. A sharpening device for ivory-saws comprising the combination of a bracket secured to the saw-frame, a plurality of posts projecting from the bracket oblique to the cutting plane of the saw and each terminating in a file-guard, a roller mounted loosely to rotate in front of each {ile-guard, and means for adjusting the bracket'and holding it in place after adjustment.

9. A sharpening device for ivory-saws comprising the combination of a bracket, two pins projecting therefrom, two conical rollers loosely mounted to rotate upon said pins, fileguards also mounted on the same bracket adjacent to the smaller ends of the rollers the faces of which are in a plane at an angle to the axes of the conical rollers, and means for -adjusting the bracket and holding it in place after adjustment.

Witness my hand this 15th day of October, 1902, at the city of Woonsocket, in the county of Providence and State of Rhode Island.

JOHN HORMBY.

Witnesses:

RALPH F. BUNKER, CHAs. SPILL. 

